Due to advances in video and audio processing technologies, multimedia content having high image quality and high audio quality is widely available. Users desire content having high image quality and high sound quality with realistic video and audio, and accordingly research into three-dimensional (3D) video and 3D audio is being actively conducted.
3D audio is a technology in which a plurality of speakers are located at different positions on a horizontal plane and output the same audio signal or different audio signals, thereby enabling a user to perceive a sense of space. However, actual audio is provided at various positions on a horizontal plane and is also provided at different heights. Therefore, development of a technology for effectively reproducing an audio signal provided at different heights via a speaker located on a horizontal plane is required.